The present disclosure relates to a fixture and socket assembly, and particularly to a socket assembly configured to receive a replaceable and flexible panel lighting device such as an organic light emitting diode (OLED) panel, as well as an associated system for attaching an array of flexible lighting devices or panels.
OLED devices are generally known in the art. An OLED device typically includes one or more organic light emitting layer(s) disposed between electrodes. For example, a cathode, organic layer, and a light-transmissive anode formed on a substrate emit light when current is applied across the cathode and anode. As a result of the electric current, electrons are injected into the organic layer from the cathode and holes may be injected into the organic layer from the anode. The electrons and holes generally travel through the organic layer until they recombine at a luminescent center, typically an organic molecule or polymer. The recombination process results in the emission of a light photon, usually in the ultraviolet or visible range of the electromagnetic spectrum.
The layers of an OLED are typically arranged so that the organic layers are disposed between the cathode and anode layers. As photons of light are generated and emitted, the photons move through the organic layer. Those that move toward the cathode, which generally comprises a metal, may be reflected back into the organic layer. Those photons that move through the organic layer to the light-transmissive anode, and finally to the substrate, however, may be emitted from the OLED in the form of light energy. Some cathode materials may be light transmissive, and in some embodiments light may be emitted from the cathode layer, and therefore from the OLED device in a multi-directional manner. Thus, the OLED device has at least cathode, organic, and anode layers. Of course, additional, optional layers may or may not be included in the light source structure.
Cathodes generally comprise a material having a low work function such that a relatively small voltage causes the emission of electrons. Commonly used materials include metals such as gold, gallium, indium, manganese, calcium, tin, lead, aluminum, silver, magnesium, lithium, strontium, barium, zinc, zirconium, samarium, europium, and mixtures or alloys of any two of more thereof. On the other hand, the anode layer is generally comprised of a material having a high work function value, and these materials are known for use in the anode layer because they are generally light-transmissive. Suitable materials include, but are not limited to, transparent conductive oxides such as indium tin oxide (ITO), aluminum doped zinc oxide (AZO), fluorine doped tin oxide (FTO), indium doped zinc oxide, magnesium indium oxide, and nickel tungsten oxide; metals such as gold, aluminum, and nickel; conductive polymers such as poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS); and mixtures and combinations or alloys of any two or more thereof.
Preferably, these light emitting or OLED devices are generally flexible, i.e., are capable of being bent into a shape having a radius of curvature of less than about 10 centimeters. These light emitting devices are also preferably large-area which means they have a dimension of an area greater than or equal to about 10 centimeters squared, and in some instances are coupled together to form a generally flexible, generally planar OLED panel comprised of one or more OLED devices, which has a large surface area of light emission.
Preferably, the panel is hermetically sealed since moisture and oxygen have an adverse impact on the OLED device or panel. It is desired that an electrical pathway be established with the light emitting panel, and also that the electrical pathway maintain flexibility, be easily and accurately positioned, establish good electrical continuity, and maintain a thin profile. Commonly owned U.S. application Ser. No. 12/644,520 describes a light panel in which at least one electrical feed-through region is provided in the backsheet located inwardly from a periphery of the light source. A connector cable is positioned over the backsheet and has a portion of the connector cable extending outwardly of the light source periphery for connection with associated drive circuitry.
A need exists for a reliable fixture and socket system configured to receive one or more flexible OLED devices, panel, or array of panels, and a reliable manner of attaching the devices, panel, or panels to the fixture. Moreover, a need exists for a reliable fixture and socket system that allows for a wide array of sizes and shapes while still providing for reliable electrical contact, effective mechanical support, and the ability to avoid potential shorting with electrical connections.